package com.gmh.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.gmh.dto.Result;
import com.gmh.dto.UserDTO;
import com.gmh.entity.Follow;
import com.gmh.mapper.FollowMapper;
import com.gmh.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.gmh.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private UserServiceImpl userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        if (isFollow) {
            //关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean success = save(follow);
            if (success) {
                String key = "follows:" + userId;
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        } else {
            //取关
            boolean success =remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if(success){
                stringRedisTemplate.opsForSet().remove("follows:" + userId, followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }

    @Override
    public Result followCommons(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key1 = "follows:" + userId;
        String key2 = "follows:" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if (intersect == null || intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> usersDTOS = userService.listByIds(ids).stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(usersDTOS);
    }
}
